Hopefully, this is the right place to post this request. I was just wondering if anybody could identify
From the cursory research that I have done, there is some variation in what qualifies as a "pork-pie hat", depending on the time period.
I have included a screen shot from the ad which shows the hat from a different angle. The crown tip ( a.k.a. the top) of the hat is not completely flat. There is a crease along the edge. It is the presence of the crease that distinguishes it as a pork-pie hat. The pic posted by the OP is a still from the Stella Artois "Be Legacy" ad campaign. The short film/advert. is set in the early 1700's. I can only assume that the costumer attempted to dress the cast in a historically accurate attire as possible.
There is conflicting information about when this style of hat first became known as a pork-pie hat. According to an online etymology website, there is documentation of the existence of pork pie, the food, as early as 1732. The earliest documentation of the term pork-pie hat was in 1855.
Also, here is a picture of a pork pie, courtesy of wikipedia. See the vague resemblance?